Fuse setting apparatus for shells



Feb, 113, 1945 v. P. HARVEY 2,369,394

FUSE SETTING APPARATUS FOR SHELLS Filed Oct. 14, 1940 2 Sheets-Sheet l llll HHIIH II iiii Feb 13, 1945. v. P. HARVEY FUSE SETTING APPARATUS FOR SHELLS 2 Sheets-Sheet 2 Filed Oct. 14, 1.940

Patented Feb. 13, 1945 FUSE SETTING APPARATUS iron SHELLS Valentine Pearce Harvey, Deptford. London, England, assignor to Molins Machine Company, Limited, London, England Application ocmber 14, 194-0, Serial .No. 361,147

In. Great Britain March 23,1939

11 Claims. .(Cl. 86 -231) holders, said means comprisinga differential gear,

This invention concerns improvements in or relating to. fuse setting apparatus for shells, such for example as 3.7 inch shells such as are used with anti-aircraft guns;

The fuses which are to be set by the apparatus 5. according to the present invention are of the kind having a fixed and a movable fuse-element, the latter being rotatable about the longitudinal axis of the shell with which the fuse is connected,

9 the setting of the fuse being determined by the relative angular positions of the fixed and movable elements. Such fuses will be referred to hereinafter as fuses of the kind described. The fixed and movable fuse-elements are provided with shoulders or abutments, and an abutment on the fixed fuse-element will be called a fixed abutmen whilst an abutment on the movable fuse-element will be called a movable abutment. These abutments are provided to enable pawls or other members in the fuse-setting appai120 ratus to register therewith for the purpose of setting the fixed and movable fuse-setting element in the. desired angular relationship.

Where the term locating element is used herein it shall be taken to mean the said pawls or the said other members.

The present invention refers to fuse-setting apparatus of the kind having-locating elements mounted in two holders rotatable about an axis coincident with the axis of a shell the fuse of which is to be set, the locating elements being adapted to engage with the fixed and movable abutments and to move the movable element of the fuse relatively to the fixed element. Such a fuse-setting apparatus will be referred to herein as a fuse-setting apparatus of the kind described.

According to the present invention there is provided fuse-setting apparatus of the kind derelative rotary movement between the two said holders, said means. comprising a differential gear, driving means operative to drive one sun gear wheel of saiddifferential gear, the second of said holders in one direction, rotation of the planet carrier of thediiferential being arranged to drive the second of said holders in the opposite direction and a train of gear wheels coupling one holder to its driving'source in-the differen- 5 relative rotary movement between the two said driving means operative to drive one sun gear wheel of said differential gear, one of the .holders being operatively connected for positive drive-in one direction by the second sun gear wheel, rotation of the planet carrier of the differential gear being arranged to drive the second of said holders and a train of gear wheels coupling one holder to its driving source in the differential, gear wheels of said train being mounted for orbital movement about the axis of rotation of the sun gear wheels to alter the relative angular positions of the said holders and means to hold the said train in any desired orbital position.

Preferablyeach of said holders is capable of rotating 360 degrees, the sum of the total angles through which the two holders turn is at least equal to 720 degrees, and means is provided to stop rotation of the driving or first said sun gear Wheel of the differential when the latter has reached a predetermined angular position. The differential gear may be of the bevel gear type,

.and the train of gear wheels preferably comprises a gear wheel fixed to the planet gear wheel carrier of the differential and meshing with one of two gear wheels on a counter-shaft, the other of said two gear wheels being arranged to mesh with the gear wheel fixed to the said second holder. Gears of said train of gears may be mounted so as to be movable through an arcuate' path about the axis of rotation of the sun gears to alter the relative angular positions of the locating elements. The counter-shaft may be journalled in a worm wheel which has its axis concentric with that of the sun gear wheels of the differential whilst a hand operated worm is arranged to mesh. with and rotates said worm wheel to. cause the counter-shaft to. move in an orbital path. Preferably a fixed stop member is mounted scribed, said apparatus having means for causing on a x part o h e tt pp ra s n is located in the path of a movable stop. member carried on a movable part of the fuse setting mechanism, whereby v the said mechanism is brought to rest by the said stops engaging one sun gear wheel being arranged t drive one only .3 anothen'whenthe first'said 'sun wheel of the differential has reached a predetermined angular position. A spring loaded catch element arranged to hold the movable stop between the catch and a fixed stop may be located in the path of the movable 'stop member in front of the fixed stop member, the catch element being depres'sible by the movable." stop only when the: latter is moving towardsv thev fixed stop. Means mentioned below may be provided to prevent operation of the. apparatus until a shell is properly located therein. Said means preferably comprises a movable control member adapted to move between a position to engage and retain against movement, a movable element of the fuse setting mechanism and another position clear of such mechanism, an actuating lever coupled to move with a cushioning device for the shell and a lost motion connection between the actuating lever and the control member, whereby the control member is adapted to be moved by the actuating lever to such clear position when a shell is properly located in the apparatus. Preferably a resilient member urges the control member towards the position to engage the said movable element of the fuse setting mechanism. The actuating lever may be adapted to engage the catch element to withdraw the latter from the path of the movable stop member after a shell is withdrawn to allow the fuse setting mechanism to be reset. Manual means may be provided for moving the control member to the said clear position at will.

Fuse setting apparatus made in accordance with the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is an end elevation of a fuse setting apparatus.

Figure 2 is a sectional side elevation partly on the line A-A, Figure 1, and partly on the line B-B, Figure 1. Everything to the left of and including the stop 68 is a section on the line AA, and the remainder is a section on the line 3-3.

Figures 3 and 4 show the pawls used for powder and mechanical fuses respectively.

Figure 5 is a fragmentary view in the direction of the arrow C, Figure 2.

Figure 6 is a side elevation on an enlarged scale of certain gearing elements shown in Figure 2.

Like reference numerals refer to like parts throughout the specification and drawings.

The fuse setting apparatus has a casing I to which is attached a art 2 and a part 3 which is removable to enable certain parts to be changed. This part 3 is provided with a hollow support which is adapted to receive the nose of the shell.

A concave roller 4 mounted on a bracket 5 pivoted at 6 to the hollow support is arranged in front of the hollow support. In Figure 2 a shell l is hown in position in the fuse setting apparatus. The nose of the shell is seen to be pressing against a slidable member 8 of a cushioning device. The slidable member 8, which has been displaced to the left in Figure 2 by the shell, has an enlarged portion which fits within a sleeve 9. A compression spring I0 acting between this enlarged portion and the sleeve 9 offers a resistance to the displacement mentioned above. A lever I I pivoted on a pin I2, has an aperture through which an extension I3 of the slidable member 8 extends. A collar I4 mounted on the slidable member 8 enables the lever II and member 8 to move one another at the appropriate times. The lever II is pivotally connected near its lower end to a rod or arm I8 attached to the piston of a dashpot I5, the dashpot being provided to resist clockwise movement of the lever I I. A-tension spring I6 anchored to a pin I1, which is also the pivot pin to the dashpot I5, tends to turn the lever I I in an anti-clockwise direction. From the description of the apparatus given so far it will be seen that on the insertion of a shell the member 8 is moved bodily towards the left hand side of Figure 2, and the collar l4 turns the-lever parts.

II in a clockwise direction against the resistance of the dashpot I5. The parts are so arranged that on the insertion of a shell the spring I0 is first compressed, and when the member 8 has been moved sufliciently far to cause the ring I4 to engage the lever II, then the resistance of the dashpot is added to that of the spring I0. An adjustable stop I9 controls the extent of movement of the lever in a clockwise direction. The dashpot I5 is mounted in the lower part of the apparatus and is arranged to be totally submerged in oil held in the casing I.

The leeve 9 previously referred to is mounted so as to be capable of rotating. To the right hand end of the sleeve 9, as seen in Figure 2, is bolted a ring 20, which acts as a holder for pawls which are adapted to engage the notch in a fuse ring 2I of the shell. A second pawl-ring 22 having pawls to engage abutments in a fuse ring 23 of the shell i bolted to a hollow rotatable member 24 which encircles the hollow sleeve 9. Roller bearings 25 and 26 are provided between the rotatable members 9 and 24, and the outer surface of the latter is supported by ball bearings 21 and 28. The outer ball race of the ball bearing 28 is mounted on a fixed part of the casing of the fuse setting apparatus.

The pawl rings 20 and 22 are arranged in the construction being described to set a powder fuse.

When it is desired to set a clockwork fuse the I pawl rings are changed and rings having pawls suitable for engaging the abutments or notches on the clockwork fuse are substituted. Figure 3 shows a part of a pawl-ring with pawls 220 suitable for a powder type fuse. The pawls are slidable radially and are spring urged inwardly to engage the fuse-ring. Figure 4 shows a part of a pawl-ring with pawls 22I suitable for the clockwork type of fuse. Except for the shape of their notch engaging portions, pawls 532i are similar to the pawls 220. To change the pawl rings, the hollow support 3 is removed and the pawl-ring 22 is unscrewed from the rotatable member 24. Next, a spacing ring 29 is removed and then the pawl-ring 20 is unscrew :d from the hollow support 9. The new pawl-rings are then substituted.

The mechanism to drive the pawl-rings is arranged as follows. A toothed quadrant 30, to which is secured an actuating lever 60, meshes with a gear wheel 3I mounted on a shaft 3| 0. The latter carries a split gear wheel 32, which in turn meshes with gear teeth 33 on a sleeve member 34. The right hand end of the sleeve member 34, as seen in Figure 2, constitutes a bevel gear wheel 35 which forms one sun. gear of a bevel differential gear. A bevel gear wheel 36 constitutes the other sun gear wheel of thi bevel differential gear and is fixed to the rotatab-le'sleeve 9 to which is secured the pawl ring 20. A planet gear wheel 31 meshes with these two sun gear wheels. The planet gear wheel is carried by a planet carrier 38 provided with gear teeth 39. and a split gear wheel 40 mounted on a countershaft 4| meshes with the gear teeth 39. A split ear wheel 42 mounted on the countershaft meshes with gear teeth 43 provided on the hollow rotatable member 24 carrying the pawl ring 22. The counter-shaft 4| is journalled in a casing 44 which is mounted on ball bearings 21 and 45 and which is adapted to rotate relatively to the other The inner race of the ball bearing 2'! engages the other surface of the rotatable member 24, and the outer race of the ball bearing 2! engages the inner surface of the casing 44. At the other end, the outer race of the ball bearing engages the inner surface of the casing N, and the inner race of this ball bearing is mounted on the sleeve member 34. E'ncirc-ling and fixed to the casing 4 4' is a worm wheel it having split teeth as shown. A worm 47 011 a shaft 53 meshes with the worm wheel 46. A bevel gear wheel 28 mounted on a sleeve splined to the shaft 53 meshes with a bevel gear wheel 49 which is mounted on a spindle 450 and is rotated by a hand wheel 55. Thi hand wheel 50 is also ar-' movement of the hand wheel 50 in either direc- 'tion, and in the construction shown this is effected as follows. A gear wheel on the spindle 490 and having 43 teeth meshes with a further gear wheel 57 mounted on an idler shaft 510 and having 42 teeth. Projections 58 and 55 are carried by the gear wheel 56 and 5'! respectively and project from hubs 58b and 590 respectively of the gear wheels. These two projections are each arranged to lie in the path of the other in known manner, and thus according to the numbers of the teeth on the gear wheels and the difference between these numbers, the hand wheel can be given a certain number of rotations in each direction before the projections 53 and 59 meet one another and prevent further rotation.

It has already been stated that the quadrant 30 has attached to it a lever arm 69. This lever arm til when pulled in a. clockwise direction as seen in Figure l operates the gears in the direction desired to set the fuse. Mechanism to stop the rotation of the main driving gears when the fuse is set and also to prevent the operation of such gears until a shell is properly located will now be described. A tail piece 6! on the lever H passes through an aperture in a catch element 62 slidable in a fixed part 53 of the apparatus. The catch 52 is spring urged towards the right hand side of Figure 2 by a compression spring 6-1 which acts against the tail piece 61. of the lever H and the body of the catch 82. The tail piece Bl also lie between the forks of a control member 65 pivoted on a pin 55 and spring urged by a. compression spring 61 to engage the quadrant 30. A fixed stop member 58' is mounted on a fixed part of the apparatus and a moving stop member or lug 69 is provided on the gear wheel 32.

The quadrant 30 is not shown in the proper position in Figures 1 and 2 relative to the other gear wheels. In the position shown in Figures 1 and 2 the stop 69 is shown held between the fixed stop 68 and the catch 62 so that the gear wheel 32 cannot be rotated in either direction. That then represents the position of the parts after a fuse has been set. The quadrant 3:1 in that case would naturally be much higher up than is shown in the figures, since t lever would be depressed and not in the up position shown in Figure 1. The arrangement of these parts can be determined from the following description. Assume the apparatus has just set a fuse, so that the parts with the exception of the quadrant 3B are in the position shown in Figures 1 and 2. On withdrawal of the shell the slidable member 8 will move to the right as seen in Figure 2, and the lever H will move in an anti-clockwise direction. This anti-clockwise movement of the lever will cause the lever H to withdrawn the catch 62 from the path of the stop 69. The tail "6| of the lever l i does not push the control member 65 over to the left owing to the large gap provided. The catch 62, however, having been withdrawn, it is now possible to rotate the lever BI] in an anti-clockwise direction to reset the apparatus. When this is done, the quadrant 30 will move down so that a detent 10 on the control member 65 will engage the top surface ll of the quadrant 30. Thus as soon as the lever arm Ell is returned to the position shown in Figure 1, the control member 65 will make it impossible to move the lever arm 68 until another shell is properly located in the fuse setting apparatus. A manually operable plunger [2 is provided for releasing the quadrant 30 from the control member 65 if it is desired to operate the mechanism without a shell being in position. A compression spring 13 holds the plunger away from the control member 65. On insertion of a subsequent shell the tail piece 6| will move to the right hand side in Figure 2. Owing to the lost motion connection between this tail piece BI and the forks of the control member 65 the latter will not be moved clear of the quadrant 30 until the very last moment, that is to say, at the moment when the shell is properly located. The catch G2 will, of course, have been moved forwardly to lie in the path of the movable stop member 59 on the gear 32. The stop member 69, however, will not then be in the position shown in Figure 2, since the mechanism, as has been mentioned before, has been reset. A shown in Figure 2, the face of the catch 62 is arranged to slope so as to enable the stop 69 to depress the catch 82 only when the stop is moving towards the fixed stop 58, that is to say, during the setting operation. The apparatus i now ready to set the fuse, and to do this the lever arm 60 as seen in Figure 1 is pulled down in a clockwise direction, The gears will be brought to rest as soon as the stop 69 has moved past the catch 52 and engaged the fixed stop 68. It will then be impossible to move the lever arm 68 in either direction.

In the example shown the gear wheels are so arranged that the sleeve member 34 and its sun gear wheel 35 (that is, the driving sun gear of thedifferential) move through just over two complete revolutions in order to ensure that the notches in both fuse rings will be engaged in whatever angular positions they may be.

When, in a fuse setting apparatus according to this invention, it is desired to ensure that pawls in each of the pawl rings will, during a setting operation, engage the fuse abutments (without the necessity of rotating or otherwise previously angularly positioning the shell), "irrespective of the relative positions of these abutments. to one another and to the pawls on the insertion of a shell into the apparatus, then the pawl ring for the fixed abutment must be capable of rotating 360", if necessary to engage the fixed abutment, and will cease to rotate when the fixed abutment is engaged, even though that be earlier than 360. In all such cases, however, the sum of the. total angular movements of the two pawl rings must always be at least equal to 720 to permit both pawl rings to rotate 360 if that b necessary to locate their respective abutments. Inthe example being, described this sum is 723 and the sun gear 35 is arranged to rotate approximately fixed and movable abutments will always be engaged and the latter positioned where desired.

It is necessary of course, that the angular relationship between the pawl rings 20 and 22 corresponds to a reading indicated by the follow-thepointer needle in the receiver at the time when the stop 69 is locked between the catch 62 and the stop 68. This is, however, a simple matter of adjustment.

From the foregoing it can be seen that when the lever arm 60 is pulled down, the driving sun gear 35 rotates. The planet gear wheel 31 rotates about its own axis, thus rotating the second sun gear 36; the pawl ring 20 is thereby rotated through the rotatable sleeve 9. Assuming that the pawls in the pawl ring 29 are not in engagement with the notch in the ring 2|, and the resistance to rotation imposed on the gear 39 is greater than that imposed on the gear 39, the

latter will rotate, whilst the planet gear 3'! will.

merely rotate about its own axis without moving orbitally. Thus the pawl rin 20 will continue to move until the pawls in the pawl ring 29 engage the notch in the fuse ring 2|. Then, whether the ring 2| is a fixed or movable ring, enough resistance will be set up to cause the planet carrier 33 to rotate so that the planet gear wheel 32' moves orbitally. Rotation of the planet carrier 38 causes the gear wheel 39 to rotate, and this in turn rotates the gears 40, 42 and 43, the latter being fixed to the member 24 which carries the second pawl ring 22, which is rotated until the pawls thereof engage the notch in the fuse ring 23. The pawl ring 22 is, as can be seen, coupled to the planet carrier 38 of the differential, and the carrier 38 is, in the example shown, the driving source in the differential for the pawl ring 22. When the notches in the ring 23 are engaged, the further rotation of the pawl rings will depend upon which is the fixed fuse ring. If the ring 23 were the fixed fuse ring, then the resistance to rotation offered by the ring 23 would be greater than the resistance torotation oifered by the ring 2|, and consequently in such a case movement from the quadrant 30 would be transmitted through the sun gear 36. The moving pawl ring would then continue to rotate until the mechanism is brought to rest by the engagement of the stop 69 with the fixed stop 68. In the example shown in the drawings the fuse is of the powder type, and in such a case the fixed ring is the ring 2|. In that case, therefore, when the pawls have engaged the notches, the pawl ring 22 is the one which will continue to rotate.

The pawl rings 29 and 22 rotate in opposite directions, and the gear wheels are so proportioned that the pawl ring 22 when moving will be moving at the same angular velocity a the pawl ring 2|] had previously moved in the opposite direction.

When, however, the driving sun gear wheel 35 has rotated through 720 the pawls in the respective pawl rings 20 and 22 will be in the same angular relationship as they were before the driving sun gear had commenced to rotate. In the example described, since the sun gear wheel 35 rotates through 2.01 revolutions, the relative angular poitions of the pawls will be slightly different, when the apparatus is brought to rest, from the position in which they were to start with, but as has been mentioned previously, this does not matter provided that the angular relationship of the pawl rings, when the stops 68 and 69 are in engagement at the end of a setting, corresponds to that indicated on the receiver dial by the follow-thepointer needle.

i i I 0 The angular relationship of the pawls is adjusted by rotating the hand wheel 50 and thus causing the worm wheel 46 to rotate in a clockwise'or anti-clockwise direction according to the direction in which the hand wheel 50 is rotated. As can be readily seen, rotation of the worm wheel 46 causes relative angular movement between the pawl rings 20 and 22. Thus the orbital position of the counter-shaft 4| controls the angular relationship of the pawls in the respective pawl rings, and the ultimate setting of the fuse elements will depend upon the orbital position of the counter-shaft 4| and also upon the position in which the driving sun gear 35 is brought to rest.

As will be seen from above, it is essential that the driving sun gear 35 should finish up a1; the same angular position at each fuse setting operation, because it is that final angular position of the driving sun gear 35 which determines whether or not the pawl rings and consequently the abutments on the fixed and movable fuse elements are in the desired angular relationship for a given orbital position of the counter-shaft 4 I. It is also essential that in all cases the relative angular movement between the two pawl rings must always be the same for a given angular movement of the driving sun wheel 35 of the differential gear.

In the construction described above a different set of pawl rings suitable for a clockwork fuse would be inserted if the apparatus were to set clockwork fuses.

In the construction described and shown in Figure 2, only one bevel gear wheel 48 has been shown, but as shown in Figure 5 another bevel gear 489 is provided. The gear wheels 48 and 489 are arranged one on each side of the bevel gear wheel 49 and mounted on a sleeve 484 keyed to the shaft 53, to provide a simple reverse gear for the worm 41. The bevel wheels 48 and 480 are so arranged that only one can mesh with the teeth of the wheel 49 at a time, see Figure 5, but they are so close to the teeth 49 that it is impossible for the wheel 49 not to be in engagement with either one or the other of the gears 48 and 480.

The shaft 53 extends through a bearing in the wall of the casing and a cap 512, Figures 1 and 5, is fitted over the end of the shaft in order to maintain the shaft 53 in either of its axia] positions. A spacing member 5H is provided and the cap 512 is tightened up on the end of the shaft. Thus when the spacing member 5' is in position gear wheels 48 and 49 will be in mesh but when the member 51| is taken away and the cap 512 tightened up the wheels 49 and 480 will be in mesh. In this way, when the shaft 53 carrying the wheels 48 and 489 is adjusted axially, it is impossible for the gear wheel 49 to become out of mesh with the train of gears. The purpose of having the gears 48 and 489 on the sleeve 484 is to enable the apparatus to be adjusted to set either type of fuse. The position of the moving and fixed fuse rings on a powder fuse is the reverse to that on the mechanical type of fuse. Consequently when it is desired to alter the angular relationship of the pawl rings for the two types of fuses the worm wheel 46 and countershaft 4| must be rotated in the reverse directions. Thus to increase the fuse length for one type of fuse the counter-shaft 4| would have to move in one direction, whereas to increase the fuse length of the other type of fuse the counter-shaft 4| would have to go in the opposite direction.

, By making the sleeve and the shaft 53 slida-bly adv.iustable as mentioned above, the direction of roesteem etion of the shaft 53 can b c os y o usihs either the ear eel 8 or th sear heel 4.8!! to ngage the sea wheel 4 so that the direction f ro ation o the hand h l 50 .f r i c ees ne o decre s ng fuse lengths ias the c s may he). will e the some r bo h pe of ess I In or er to reduce c lash between he w eel 4 -and the whee s 4- and B", the spindle 4. is diustably mou. ted- A u h #9! ing on ex.- ternal screw thread 492 encircles the spindle 499.: A cover 493 an internal thread which screws o r t e 'loush.-. An in ernal flange 494 engages a sho d r 4. on the s indle 9 W sher .95 c m ed in pos i n by th ha d whee i l engages the other iaceo the flan e 4% s. the co e 93 s o ated in one d rection o he ot so the flan e 494 wi so ry the s ind 4 9 w t it In: d m ement oi the spind e 9c s. lim ted by the a e 9 4 en aging the end or the hush 49!, External teeth 4. 1 out on the cove 493 engage a knife 4.9.8. he lat r is arra g d s as to be capable f e n diseneeeed f om. the. teeth 49 whenever the cover 4 3' is to he ota ed to ad st the spindle 490'.

The spl gear Wheel 3.2, t, 42 an also enable the amou o b ck sh to he reduced since the two halves can be ediu tetl o take up any unu bac sht will he obser ed that mportent iea ure of the construction. e cribed is that he su gear 36 s r anged to d ive only the paw rin 2 end the other pawl ring 22 is arranged o be d iven y ro at on of plan t ca r e 3. n the construotion descr bed. a tr in of gear wheels, incl din the g ar heels 4!! and 42 on the counter-- shaft 4 c ples the pewl rin .22 to its. sou c of dr v pow in the di lerent al, nam ly to the planet carrier, d the gear wheel 39 fixed to it: y i nstruction. the cou ter-shaft is enabled to. be moved by the w rm-whe l end o m in an bi al path a out the axis, of oti n o t e sun ear wheels .35 and hi worm and. worm-whee device ompri e means for holding the counter-sha t 4 in any des ed.

rb tal position It is cle r tha i s only by roion of the hand-wh l 50 and t e o m. H t at th orm-whe l 4.6 will rotet at al Th itel movement of the un ershett alt rs the relative angular Positions of the pawl r gs 20 nd 2 end. his can e .done at an time one is qu nd pendent of the op atio o h me n er of the anpe atu it wil he i ted at in o de to ob in t e des re ad u tme of the relative p iti ns of thev howl i s the.

ratio of gears 3.9 a d 40 must, n the spe fic em.- odiment i lust e herei i ie fr m the r tio of the e s 4 and sin e o e wise e o b ta displac ment o ea s end 4 w uld no affect t e. posit on of ther gea of cou se obv ous. th t rota ion of the wo m wheel 6 will a ter th e a e posi ion o t p w gs, an conse uent y h 1 th u e ines eve after th whee 2 is ooh deee n al m v ment he or eneement also nables gree aoracv Of set ing be o ained cl e to th laree d amete of the w m wheel 46 com are i h that f en the a e pa l in h s any iven angu ar setti is c n o led y a re t ly ns a e. o th worm wheel .5- 13 ob ain. simi u acy of se tin withou pro id n tor orbital movemen of cert in sea s connectin a pawl rin o its d ivi sou ce i the i er nt a about the axis oi e s n gea wheels would equ re considerable inc ease n. the overa si e of the. p a us:

in t e t a n I What we claimas our invention and desire to secure by Letters Patent is;

1. Fuse-setting apparatus having rotatable holders, locating elements mounted in. said hold ers and adapt d to en age with fixed and move able abutments on the body of. a fuse, means for causing relative rotary movement between the two said holders, said means comprising a differential gear driving means operative to drive one s n gear whe l f said diiiere ti l g a means to limit the angular displacement of the sun, gear Wheel to a predetermined amount,- the second sun gear wheel being. operatively c011: nect d to one on y of said h lders to dr ve the same in one direction, the planet carrier of the if erential being. operatively connefited to th second, of said holders to drivethe same in the opposite direction, one of such operative connectio s comprising a train'of gear wheels coupling one holder to its d iving source in t e d fier ential, the e i bei such hat h sum of the to al an les through which he two holders. turn is at least equal to 720.

2. Fuse-s i apparatus having rotatable holders, l cating elements mounted in said holders and adapted to engage with fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a dinerential gear, driving mea s operative to drive one sun gear wheel or said. differen ial sear, means to i t the angular displacement of the sun gear wheel to a. predetermined amount, one of the holders being operatively connected to the sec;- ond sun gear whee so as to be driven in one ,direction thereby, the planet carrier of the difteren ial s ar being operative y connected to the second of the said holders to drive, the some in the opposite direction, one of such operative connections com rising a train of gear Wheels coupling one holder to its driving source in the differential, a pair of gear wheels of said train of difierent pitch diameter being mounted for orbital movement about the axis of rotation of the sun gear wheels toalter the relative, ang lar positions of the said holders and means to hold the said train in any desired orbital position, the gearing being such that the sum of the total angles through. vvzlaich the two holders turn is at least equal .to

3. Fuse-setting apparatus having rotatable holders, locating elements mounted in said holders and adapted to engage with ,fiXecl a d movable abutment-vs on the. body of the. fuse, means for causing relative rotary movement between the two. said holders, said means comprising a, differential gear of the bevel gear type, driving means operative to drive one Sun gear wheel of' said difierential gear, the second sun gear wheel b ing operatively connected to one only of said holder to drive the same. in one direction, the planet carrier of the differential being operr atively connected to the'seco d of said holders to drive the same in the. oppositeldirection, one of such operative connectionscomprising a train of gear wheels coupling one holder to its drivihg source in the difierenti ll, said trainof gearwheels comprising a gear-wheel fixed to the planetcari r d meshin w thone of twogea'r wheels of different itch .clinmeter. on a counter sha'ft; the other f said wo gear wheels being arranged to mesh with a gear wheel co ple to the saidsec- 0nd holder.

F se-settine appar tus. having rotatable ol ers v e ne em n s no n e -i said hol ers and adapted to engage with fixed and movable abutments on the body of the fuse, means for causing relative rotary movement between the two said holders, said means comprising a differential gear of the bevel gear type, driving means operative to driveone sun gear wheel of said differential gear, one of the holders being operatively connected to the second sun gear wheel so as to be driven in one direction thereby, the planet carrier of the differential gear being operatively connected to the second of the said holders to drive the same in the opposite direction, one of such operativeconnections comprising a train of gear wheels coupling one holder to its driving source in the differential, said train of gear wheels comprising a gear-wheel fixed to the planet carrier and meshing with one of two gear wheels of different pitch diameter on a counter-shaft, the'other of said twogear wheels being arranged to mesh with a gear wheel coupled to the said second holder, said two gear wheels being mounted fororbitalrnovement about 7 the axis of rotation of the sun gear wheels to alter 1 the relative angular position of the said holders, and means to hold said, two gear wheels in any desired orbital position. I

' 5. Fuse-setting apparatus having rotatable holders, locating elementsmounted in said holders and adapted to engage with fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a diiferen tial gear of the bevel gear type, driving means operative to drive one sun gear wheel of said diiferential gear, means to limit the angular displacement of the sun gear wheel to a predetermined amount, the second sun' gear wheel being operatively connected to one only of said holders to drive the same in one direction, the planet carrier of the difierential being operatively connected to the second of said holders to drive the same in the opposite direction, one of such operative connections comprising a train of gear Wheels coupling one holder to its driving source in the diiferential, said train of gear-wheels comprising a gear wheel fixed to the planet carrier and meshing with one of two gear wheels of different pitch diameter on a counter-shaft, the other of said two gear wheels being arranged to mesh with a gear wheel coupled to the said second holder, the gearing being such that the sum of the total angles through which the two holder turn is at least equal to 720.

6. Fuse-setting apparatus having rotatable holders, locating elements mounted in said holders and adapted to engage with fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a differential gear of the bevel gear type, driving means operative to drive one sun gear wheel of said difierential gear, means to limit the angular displacement of the sun gear wheel to a predetermined amount, one of the holders being operatively connected to the second sun gear wheel so as to be driven in one direction thereby, the planet carrier of the diiferential gear being operatively connected to the second of the said holders to drive the same in the opposite direction, one of such operative connections comprising a train of gear wheels coupling one holder to its driving source in the dilferential, said train of gear-wheels comprising a gear-wheel fixed to the planet carrier and meshing with one of two gearwheels of different pitch diameter on a countershaft, the other of said two gear wheels being arranged to mesh with a gear wheel coupled to the said second holder, said two gear wheels being mounted for orbital movementabout the axis of rotation of the sun gear wheels to alter the relative angular position of the said holders, and

means to hold said two gear wheels in any desired orbital position, the gearing being such that the er and adapted to engage with fixed and movable abutments on the body or the fuse, means for causing relative rotary movement between the two said holders, said means comprising a dii ferential gear of the'bevel gear type, driving,

means operative to drive one sun gear wheel of said difierential gear, the second sun gear wheel beingoperatively connected to one only of said holders to drive the same in one direction, the

, planet carrier of the differential being operatively connected to the second of'said holders to drive the same in the opposite direction, one of such operative connections comprising a train of gear wheels coupling oneholderto its driving source in the diiferential, said train of gear wheels comprising a gear-wheel fixed to the planet carrier and meshing with one of two gear wheel of different pitch diameter on a counter-shaft, the other of said two gear wheels being arranged to mesh with'a'gear wheel coupled tothe said second holder, a worm wheel which has its axis concentric with that of the sun gear wheels, means journalling said 'co'unter sha-ft in said worm wheel, and a worm arranged to mesh with and rotate said worm wheel to cause the counter shaft to move in an orbital path.

8; Fuse-setting apparatus having rotatable holders, locating elements mounted in said holders and adapted to engage with fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a differential gear of the bevel gear type, driving means operative to drive one sun gear wheel of said differential gear, means to limit the angular dis placement of the sun gear wheel to a predetermined amount, the second sun gear wheel being operatively connected to one only of said holders to drive the same in one direction, the planet carrier of the differential being operatively connected to the second of said holders to drive the same in the'opposite direction, one of such operative connections comprising a train of gear wheels coupling one holder to its driving source in the differential, said train of gear-wheels comprising a gear wheel fixed to the planet carrier and meshing with one of two gear wheels of different pitch diameter on a counter-shaft,- the other of said two gear wheels being arranged to mesh with a gear wheel coupled to the said second holder, the gearing being such that the sum of the total angles through which the two holders turn is at least equal to 720, a worm wheel which has its axis concentric with that of the sun gear a fuse, the combination with a planet gear train' including a driving member and two driven members. said driven members being respectively operatively connected to said holders to drive the member, and means for adjusting the position of said reactive member to advance or retract the associated holder with respect to the other holder prior to operation of said first planet gear train, thereby to predetermine the fuse-setting.

10. Fuse-setting apparatus having rotatable holders, locating elements mounted in said holders and adapted to engage with the fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a difierential gear, and driving means operative to drive one sun gear wheel of said differential gear, the second sun gear wheel being operatively connected to one only of said holders to drive the same in one direction, the planet carrier of the differential being operatively connected to the second of said holders to drive the same in the opposite direction.

11. Fuse-setting apparatus having rotatable holders, locating elements mounted in said holders and adapted to engage with the fixed and movable abutments on the body of a fuse, means for causing relative rotary movement between the two said holders, said means comprising a differential gear, driving means operative to drive one sun gear Wheel of said differential gear, one of the holders being operatively connected to the second sun gear wheel so as to be driven in one direction thereby, the planet carrier of vthe differential gear being operatively connected'to the second of the said holders to drive the same in the opposite direction, one of such operative connections comprising a train of gear wheels coupling one holder to its driving source in the differential, a pair of gearwheels of said train of different pitch diameter; being mounted for orbital movement about the axis of rotation of the sun gear wheels to alter the relative angular positions of the said holders, and means to hold said orbitally mounted gear wheels in any desired orbital position.

VALENTINE PEARCE HARVEY. 

